Adding principal stress evaluation under plane strain conditions.
Fixed some warnings.
Split datastream into .C file. Removed unused, broken, StringDataStream.
Removed unfinished quad1mindlinshell3d from cmakelists.txt
Fixing up a bunch of warnings found by cppcheck: Mostly avoiding using old style C-casts. A few bugs where found in the process of using static_cast explicitly. Also using local scopes for loop counters, which again identified a few bugs.
Added some elements (e.g. wedges, Trefftz hybrid element), materials (e.g. gradient damage, large-strain master material) and much more ...
Added some elements (e.g. wedges, Trefftz hybrid element), materials (e.g. gradient damage, large-strain master material) and much more ...
Fix a few CppCheck warnings.
Tidying up new files.
Merge branch 'master' of github.com:Micket/oofem into XFEMDevelopment

Conflicts:
	src/main/usrdefsub.C
	src/oofemlib/classtype.h
	src/oofemlib/dofiditem.h
	src/sm/compodamagemat.C
	src/sm/layeredcrosssection.C
	src/sm/mps.C
	src/sm/planstrssxfem.C